Railroad-signal



(No MQdel.)

A. HOFFMAN.

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UNITED STATES lPATENT trice.

ADAM HOFFMANN, on ALLEGHENY, PENNSYLVANIA.

RAILROAD-SIGNAL.

SPECIFICATION forming part of Letters Patent No. 313,936, dated March 17, 1885.

Application filed March 3, 1884.

T all whom it may concern.- Be it known that I, ADAM HOFFMANN, a citizen of the UnitedStates, residing at Allegheny, in the county of Allegheny and State of Pennsylvania, have invented certain new and useful Improvements in Railroad-Signals, of which the following is a specification, reference being had therein to the accompanying drawings.

My invention relates to an improvement in devices for giving trains running on a singletruck railroad notice of an approaching train from an opposite direction by sounding an alarm-bell in the engineers cabin; and it consists in the combination of cranked shafts which operate under the rails, operating-levers connected to the cranks, rods which ex- `nal-rod, and the connection with the bell.

In describing my invention it is to be un' derstood that at both sides of the railroad the device for sending ahead an alarm is alike,

and what is stated about the appliance hereinafter is applicable to both sides of the road.

A represents detachedsections of a singletrack railroad, of which B are the ties and C the rails. Parallel with and near to the lat- .ter are two interrupted lines of iron rods, D, guided in staples on top of the tiesto hold them in place, but allowing them to be moved horizontally back and forward. The rods D are of a length to enable the engineer of a train in motion, when an alarm isreceived, to arrest its `progress before or at the time when it arrives at the end of the rod which gives the signal. lOn either side of the track is placed a rod, D, which should preferably be about three thousand feet long. A second similar rod is placed parallel to the rod D, overlapping it about one .thousand feet, or one-third of its length. This arrangement is proceeded with to the end of the line, aspace of about one thousand feet, or one-third the (No model.)

length of the rods, being left between the rods where they are separated, as shown at Fig. 3.

The mechanism by which the signallingis accomplished is hereinafter set forth; but the operation ofthe overlapping rods may be fully described here. Train A', traveling in the direction indicated by the arrow, arriving at a', sends the alarm ahead three thousand feet to b. The train B', running in the opposite direction, having arrived at or near b, receives the alarm one thousand feet, or more, in ad- Vance of A, and has time to stop or reverse its engine, and the reverse takes place if B sends the alarm ahead. trains running in opposite directions can communicate with one another, which they can not do by one or two continuous lines. There will be always at least one-third ofthe length of the rods between two trains when they are notified of each others approach, or as great a distance as is left open between the rods.

At the sides of the ties B,under the rods D, at suitable distances from one another, are hinged short signal-rods a with slots x, through which the rods D pass, and on the rods D are collars or pins y, that prevent their sliding through the slots when drawn to either side, that by moving the rods D the signal-rods a are made to stand erect or to incline toward the ground.

Near the ends ofthe rods D are crank-shafts b, passing under the rails from one side of the track to the other, secured in place in any suitable manner to revolve, and to one end of each is rigidly attached a lever, d, to the end of which the rod D is pivoted. The throw of the crank on the shaft b is up and down entirely beneath the rail, and over it a treadle, g, close to` the rail. wilhils rear end hinged to t-he nearest tie, and its forward end raised higher than the adjoining rail, so as to become depressed by the wheels of a tra-in arriving at thehingcd end of the treadle. The

By this means two side toward the rail of the raised end of the treadle g is cut slauting to form an opening for the wheels of a train coming from that side to enter and push away the treadle from the rail without depressing it, to be immediately IOO the crank passes, causing the crank to turn down at each depression of the treadle. The lever d, afiixed to the crankshaft, being moved when the crank is pressed down by the treadle, draws the rod D with it, causing the treadle on the other end of the same rod and the signal-rods a along the wholelength of it'to rise. If, then, the rod D were threethousand feet long, the signal-rods would be raised three thousand feet ahead of the train,whieh signals, when the train passes over the second treadle at the end ofthe same rod, are again bent low, and the first treadle raised up by the contrary motion of the rod. Before arriving, however, at the end of this same rod the wheels meet the treadle on the end of the next rod, and send the signal ahead before the former rods are bent down again, and this is repeated until the train stops.

The end of the crank-shaft b opposite the treadle is bent at a right angle, h, and to this end is pivoted a rod extending back a short distance to a single signal-rod, t', which, whenthe trcadle opposite to it is depressed, is raised to give notice to afollowing train of the nearness of a train ahead. This signal is again bent down when the treadle is raised at the lver, Z, which is connected at one end by a .chain with a bell in the engineers cabin, which lever cornes in contact with the signal-rods -raised ahead bya train approaching from an opposite direction. It' the hangers are placed on the left side under the engine, they strike the signals on that side, but those on the right hand are not struck by said engine, and as each engine raises Ithesignals on the side opposite to its hangers no false alarm can be given.

In ease two engines ruiming in the same direction should arrive at about the same time at the two ends of one of the rods D, and the one at the right of Fig. l should be upon lever g when the engine at the other end should be running upon its lever g, a break would unavoidably occur. This is prevented by placing a spring,f, at one end of each rod D, a

spring strong enough to resist the ordinary action of a single train passing over the treadle, but yielding when two of them are brought to bear against it at the same time.

The treadles g are so adjusted at the ends of the rods D that the rst one arrived at is depressed to the level of the rails, and the one at the other end thereby raised up to come successively in contact with the-wheels and be depressed, whereby the former is raised up ready for a following train to give the signal to any approaching train from the opposite direction. The rods D are thus at every passage of a train drawn back and forth, and the signal-rods raised to give a warning in advance, to again be lowered when the wheels have passed over the second treadle onthe same rod. v

Instead of only using one hanger, two may be hinged to an engine, one at each side, so

that either one can be raised up to avoid a Contact with the signals when running backward.

Having thus described my invention, I claim- 1. In a railroad-signal, the combination of the track, the rods D, placed alongside thereof and made to overlap each other, cranks, levers for movingthe rods, and signal-rods which are operated by the endwise movement of the rods, substantially as shown.

2. In a railroad-signal, the combination of the track, the rods D, placed alongside thereofl and made to overlap at their ends, cranks, op-

erating-levers connected tothe cranks, signalrods, and a mechanism on the locomotive which is for sounding an alarm and which is operated by the signal-rods, substantially as described.

3. The combination of the rods D, crank@ AD AM HOFFMANN.

XVitnesses:

Louis Monsun, RUDOLF Kovarson. 

